In magnetic recording tapes for video and audio recording, the surface of the magnetic layer is generally made smooth to improve sensitivity and output, particularly in a high frequency region.
It has also been proposed to provide a backing layer to improve the running properties of such magnetic tapes as described, for example, in U.S. Pat. No. 4,135,031. However, conventionally used backing layers have rather coarse surfaces, and their unevenness tends to be imprinted on the magnetic layer.
In order to produce video tapes having higher S/N and to improve the packing density of ferromagnetic particles therein, it has been proposed to make the ferromagnetic particles finer and to reduce the amount of additive particles other than ferromagnetic particles, e.g., the amount of carbon black to a value as small as possible. However, when the ferromagnetic particles are made finer and the amount of carbon black in the magnetic layer is reduced, the optical density decreases, and the magnetic tapes tend to stop running and to become electrically charged, resulting in deterioration of the running durability of the tapes.